.TH MOOSEFS "7" "November 2009" "MooseFS 1.6.9"
.SH NAME
MooseFS \- networking, distributed, fault-tolerant file system
.SH DESCRIPTION
.PP
MooseFS is a networking, distributed file system. It spreads data over several
physical localisations (servers), which are visible to a user as one resource.
For standard file operations MooseFS acts as other Unix-alike file systems. It has
hierarchical structure (directory tree), stores files' attributes (permissions,
last access and modification times) as well as makes it possible to create
special files (block and character devices, pipes and sockets), symbolic links
(file names pointing to another files accessible locally, not necessarily on
MooseFS) and hard links (different names of files which refer to the same data on
MooseFS). Access to the file system can be limited basing on IP address and/or
password.
.PP
Distinctive features of MooseFS are:
.TP
 - higher reliability (data can be stored in several copies on separate computers)
.TP
 - dynamically expanding disk space by attaching new computers/disks
.TP
 - possibility of storing deleted files for a defined period of time ("trash
   bin" service on a file system level)
.TP
 - possibility of creating snapshot of a file, which means coherent copy of the
   whole file, even while the file is being written.
.SH ARCHITECTURE
.PP
MooseFS installation consists of four types of machines:
.TP
 - managing server (\fBmfsmaster\fR(8)) - single computer managing the whole filesystem,
   storing metadata for every file (information on size, attributes and file
   localisation(s), including all information about non-regular files, i.e.
   directories, sockets, pipes and devices).
.TP
 - data servers (\fBmfschunkserver\fR(8)) - any number of commodity servers storing files
   data and replicating it among themselves (if a certain file is supposed to
   exist in more than one copy).
.TP
 - metadata backup servers (\fBmfsmetalogger\fR(8)) - any number of servers, all of
   which store metadata changelogs and periodically downloading base metadata file;
   it's easy to run \fBmfsmaster\fR(8) process on such machine when primary master
   stops working.
.TP
 - client computers referring to MooseFS stored files - any number of machines with
   working \fBmfsmount\fR(8) process that communicates with the managing server to
   receive and modify file information and with chunkservers to exchange actual
   file data.
.PP
Metadata is stored in memory of the managing server and simultaneously is being
saved on disk (as a periodically updated binary file and immediately updated
incremental logs). The main binary file as well as the logs are replicated to
metaloggers (if present).
.PP
File data is divided to fragments (chunks) of maximum size 64MB each which are
stored as files on selected disks on data servers (chunkservers). Each chunk is
saved on different computers in a number of copies equal to a "goal" for the
given file.
.SH "REPORTING BUGS"
Report bugs to <bugs@moosefs.com>.
.SH COPYRIGHT
Copyright 2008-2009 Gemius SA.

MooseFS is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, version 3.

MooseFS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with MooseFS.  If not, see <http://www.gnu.org/licenses/>.
.SH "SEE ALSO"
.BR mfschunkserver (8),
.BR mfsmaster (8),
.BR mfstools (1),
.BR mfsmount (8)
